I have a problem with my second monitor. My primary monitor is connected via VGA->DVI and my second via a DVI both plugged into one DVI port with a dual cable. I have had this setup for over 2 years - working fine.

This morning I wanted to check an other PC so I took out the dual cable and put it into the test PC. After the test I plugged it back in. However, now only my primary (VGA) monitor works, my secondary (DVI) light is flashing until login screen; then tells me “ No signal”. OS is Windows 7.